苏云金芽胞杆菌含不同质粒和不同基因工程菌的生长代谢

用微量热法研究了世界上产量最大的微生物杀中心剂苏云芽胞杆菌(Bacillusthuringiensis)野生菌株YBT－1463，无晶体突变株BMB160和无质粒、无晶体突变株BMB171以及含量不同杀虫蛋白基因工程菌BMB－304－171－A和BMB－304－171－B的生长代谢动力学变化。结果是，含有14个质粒的野生菌株YBT－1463的生长代谢热比无晶体含6个质粒的变株BMB160和无晶体、无质粒突变株BMB171低；将杀虫晶体蛋白基因vryⅠAc和cryⅠC分别转入受体菌BMB171中后，两个工程菌BMB－303－171－A和BMB－304－171－B生长代谢热与受体菌BMB171相比也吸显降低；表明质粒形成一个耗能过程，当受体菌BMB171转入杀虫晶体蛋白基因后，工菌比受茶杯菌的放热大幅度减少，表明基因编码杀虫晶体蛋白也是一个耗能过程，但是含基因cryⅠAc和cryⅠC工程菌BMB－304－171－A和BMB－304－171－B之间的生长代谢没有明显差异。首次报道这些热动力学变化，对杀虫剂发酵生产过程的代谢控有重要指导意义。

Thermokinetic change of several bacillus thuringiensis strains including different plasmids or having different genes as studied by microcalorimetry

The heat out -put of metablism of different bacillus thuringiensis has been studied by means of microcalorimetry. The experimental strains were a wild type (YBT-1463) and engineering type (BMB160, bmb171, BMB-304-171-A, BMB-304-171-B). YBT-1463 contains fourteen plasmids, BMB160 contains six plasmids but no insecticidal crystal protein. BMB171 have neither plasmids nor insectividal crystal protein gene. BMB-304-171 -A and BMB-304-171- B each havew a insecticidal crystak protein gene , one is the gene of cryⅠ Ac the other is ctyⅠC. The experimental data show that the heat out -put of metabolism of BMB171 is much more than that of YBT-1463 and BMB160, and the metabolic heats of BMB-304-171-A and BMB-304-171-B are also less than that BMB171. These results indicate that the endogenuous plasmids have great effect on the metabolism of Bacillus thuringiensis. It is the same for the genes which are tranformed into BMB171. sime there is no much difference between the genes of cryⅠAc and ctyⅠC, there is no dramatic change in thermokinetism. The first report of the thermokinetism in Bacillus thuringensis is benficial to the control of fermention .